Search

Hon Shing Ong,1–3 Mohamed Farook,1 Benjamin Boon Chuan Tan,1 Geraint P Williams,1,2 Marcony R Santhiago,4,5 Jodhbir S Mehta1–3,6 1Department of Corneal and External Diseases, Singapore National Eye Centre, Singapore, Singapore; 2Tissue Engineering and Stem Cell Group, Singapore Eye Research Institute, Singapore, Singapore; 3SingHealth Duke-NUS Ophthalmology and Visual Sciences Academic Clinical Programme, Duke-NUS Graduate Medical School, Singapore, Singapore; 4Department of Ophthalmology, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil; 5Department of Ophthalmology, University of Sao Paulo, Sao Paulo, Brazil; 6School of Material Science and Engineering, Nanyang Technological University, Singapore, SingaporeCorrespondence: Hon Shing Ong; Jodhbir S MehtaDepartment of Corneal and External Diseases, Singapore National Eye Centre, 11 Third Hospital Avenue, Singapore168751, SingaporeTel +65 6227 7255Email honshing@gmail.com; jodmehta@gmail.comPurpose: A percentage tissue altered (PTA) score of ≥40% has been advocated as an independent indicator of post-operative ectasia risk following laser in-situ keratomileusis (LASIK). This study was performed to test the hypothesis that refractive procedures, such as laser-assisted sub-epithelial keratectomy (LASEK) or small incision lenticule extraction (SMILE), may alter the range of PTA, within which refractive corneal surgery can be safely performed.Setting: Refractive department, tertiary ophthalmic hospital.Design: Retrospective observational study.Methods: Review of case notes was performed for patients who presented for refractive surgeries, other than LASIK. To determine the risk of corneal ectasia for each patient prior to refractive surgery, we estimated what each patient’s PTA would have been if they had undergone LASIK. The Randleman Ectasia Risk Score System (ERSS) was also calculated.Results: 114 eyes (66 patients) were included. 94 eyes underwent SMILE. 20 eyes underwent LASEK. A significant proportion of eyes had PTA ≥40% – SMILE eyes: up to 31.9%, LASEK eyes: up to 60.0% (at presumed LASIK flap of 120 μm). The maximum calculated PTA was up to 47.9% in the SMILE group and up to 51.5% in the LASEK group. Using ERSS, 12.8–16% of SMILE eyes and 15.0–80.0% of LASEK eyes would have been considered to have moderate-to-high ectasia risk. No post-surgical ectasia was observed at 3 years.Conclusion: SMILE and LASEK alter the range of PTA, within which corneal refractive surgery may be performed with a lower risk of developing post-operative corneal ectasia; a safe PTA threshold needs to be determined for these procedures before recommendations for clinical practice can be made.Keywords: percentage tissue altered, ectasia, refractive surgery, laser in situ keratomileusis, laser-assisted sub-epithelial keratectomy, small incision lenticule extraction

Audrey Pang,1,2 Karim Mohamed-Noriega,1 Anita S Chan,1,3–5 Jodbhir S Mehta1,3 1Singapore National Eye Centre, 2Department of Ophthalmology, Tan Tock Seng Hospital, 3Singapore Eye Research Institute, 4Department of Histopathology, Pathology, Singapore General Hospital, 5Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore Background: This study describes the in vivo confocal microscopy findings in two patients who had deep anterior lamellar keratoplasty (DALK) following Descemet's stripping automated endothelial keratoplasty (DSAEK). Methods: The study reviewed the cases of two patients who first underwent DSAEK followed by DALK when their vision failed to improve due to residual stromal scarring. In the first case, a DSAEK was performed for a patient with pseudophakic bullous keratopathy. After surgery, the patient's vision failed to improve satisfactorily due to residual anterior stromal opacity and irregularity. Subsequently, the patient underwent a DALK. The same two consecutive operations were performed for a second patient with keratoconus whose previous penetrating keratoplasty had failed and had secondary graft ectasia. In vivo confocal microscopy was performed 2 months after the DALK surgery in both cases. Results: At 3 months after DALK, the best-corrected visual acuity was 6/30 in case 1 and 6/24 in case 2. In vivo confocal microscopy in both cases revealed the presence of quiescent keratocytes in the stroma layers of the DSAEK and DALK grafts, which was similar in the central and peripheral cornea. There was no activated keratocytes or haze noted in the interface between the grafts. Conclusion: Our short-term results show that performing a DALK after a DSAEK is an effective way of restoring cornea clarity in patients with residual anterior stromal opacity. In vivo confocal microscopy showed that there were no activated keratocytes seen in the interface of the grafts, which suggests that optimal visual acuity may be obtained with minimal interface haze. Keywords: cornea, transplant, keratocytes, histology

Errol W Chan,1 Tina T Wong,2,3 Hla M Htoon,3 Ching L Ho,2 Donald T Tan,1,2,3 Jodhbir S Mehta2,3,4 1Department of Ophthalmology, National University Health System, Singapore; 2Singapore National Eye Centre, Singapore; 3Singapore Eye Research Institute, Singapore; 4Department of Clinical Sciences, Duke-NUS Graduate Medical School, Singapore Objective: To compare the 3-year incidence of de novo ocular hypertension (OHT) after Descemet stripping automated endothelial keratoplasty (DSAEK) and penetrating keratoplasty (PK). For DSAEK, to evaluate predictors for OHT and 2-year outcomes after OHT development. Methods: This was a review of the prospective Singapore Corneal Transplant Study at a single tertiary referral center. Consecutive DSAEKs and PKs for Fuchs’ endothelial dystrophy (FED) and pseudophakic bullous keratopathy (PBK) in eyes without pre-existing glaucoma were analyzed. OHT incidence after DSAEK and PK were compared using Kaplan–Meier survival analysis, and OHT risk factors identified using Cox proportional regression. OHT was defined: intraocular pressure (IOP) ≥ 24 mmHg or ≥ 10 mmHg from baseline. Secondary outcomes 2 years after OHT development in DSAEK were rates of glaucoma medical therapy failure, IOP success, graft failure and rejection, and best-spectacle corrected visual acuity (BSCVA). Results: There were 108 (96.4%) DSAEKs and 216 (96%) PKs. The 1-, 2- and 3-year de novo OHT incidence was not significantly different between DSAEK (36.1%, 47.2%, 47.2%, respectively) and PK (35.7%, 44.9%, 45.8%, respectively; P = 0.914). OHT incidence did not differ in subgroup analyses of multiple clinical variables (P > 0.1). OHT predictors after DSAEK were: fellow eye glaucoma (hazard ratio [HR] 3.20, P = 0.004), age

Tien-En Tan,1,2 Jodhbir S Mehta2–4 1Yong Loo Lin School of Medicine, National University of Singapore, Singapore; 2Singapore National Eye Centre, Singapore; 3Singapore Eye Research Institute, Singapore; 4Department of Clinical Sciences, Duke-NUS Graduate Medical School, Singapore Abstract: Intrastromal corneal inlays are an emerging treatment for presbyopic patients. The KAMRA™ small aperture inlay was the first such inlay to receive Conformité Européenne (CE) marking in 2005. It has been shown to improve uncorrected near and intermediate visual acuity without adversely affecting uncorrected distance visual acuity. Due to the age of presbyopic patients, they may eventually develop cataracts. In two such cases, we found that cataract surgery with the KAMRA implant left in place was not technically more difficult, and that the surgical procedure could be improved by additional ocular rotations to improve visualization. Biometry readings were reliable, and it appeared that the SRK/T formula was accurate for calculation of intraocular lens power. Cataract surgery with the KAMRA implant left in situ is a viable option for patients. Keywords: cataract surgery, KAMRA, corneal inlay, AcuTarget, presbyopia

Hsi-Wei Chung,1 Jodhbir S Mehta1–31Singapore National Eye Centre, Singapore; 2Tissue Engineering and Stem Cell Group, Singapore Eye Research Institute, Singapore; 3Department of Clinical Sciences, Duke-NUS Graduate Medical School, SingaporePurpose: To evaluate the feasibility of fibrin glue in Gundersen flap surgery.Design: Prospective case series.Study subjects: Seven eyes of seven subjects who had undergone Gundersen flap surgery from 2009 to 2011 at the Singapore National Eye Centre, Singapore.Methods: Review of case records for outcomes after Gundersen flap surgery.Main outcome measures: Surgical success was defined as achieving a stable ocular surface. Complications to be noted included flap retraction or exposure of underlying corneal surface.Results: Surgical success was achieved in all eyes with significant reduction in ocular surface inflammation. No retractions were noted and recovery was uncomplicated.Conclusion: Fibrin glue application is a viable alternative to sutures in Gundersen flap surgery. It reduces surgical downtime, gives faster ocular surface rehabilitation, and offers similar outcomes to conventional conjunctival flap surgery.Keywords: Gundersen, conjunctival flap, fibrin glue

Andrea Petznick,1 Annabel Chew,2 Reece C Hall,2 Cordelia ML Chan,2 Mohamad Rosman,1,2 Donald Tan,1–3 Louis Tong,1–4 Jodhbir S Mehta1–31Singapore Eye Research Institute, Singapore; 2Singapore National Eye Centre, Singapore; 3Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; 4Duke-NUS Graduate Medical School, SingaporePurpose: To evaluate longitudinal changes in corneal sensitivity, tear function, and corneal staining in patients who underwent laser in situ keratomileusis (LASIK) using two different femtosecond lasers.Methods: In a prospective, randomized clinical trial, contralateral eyes of 45 patients underwent flap creation by either VisuMax or IntraLase™ femtosecond laser. Corneal sensitivity, tear break up time (TBUT), Schirmer’s test, and corneal fluorescein staining were assessed preoperatively and at 1 week, 1 month, and 3 months postoperatively.Results: There were no statistical differences in any clinical outcome measure between the two femtosecond lasers (P > 0.05), although there was a trend towards slightly lower reductions for corneal sensitivity and TBUT in VisuMax-operated eyes. Overall, corneal sensitivity was significantly reduced at 1 week (P < 0.05), 1 month (P < 0 .001), and 3 months (P < 0.001) postoperatively. A significantly greater reduction of corneal sensitivity was noted in eyes with a myopic spherical equivalent of −6.00 diopters (D) to −11.25 D as compared with eyes that had a relatively lower level of myopia of less than −6.00 D (P < 0.001). TBUT and Schirmer’s test values were significantly diminished at 1 week postoperatively (P < 0.04). Overall, corneal staining was significantly increased at 1 week postoperatively (P < 0.001). The level of myopia did not significantly affect postoperative changes in TBUT, Schirmer’s test values, or corneal staining (P > 0.05).Conclusion: This study showed that changes in corneal sensitivity, tear function, and corneal staining were statistically similar in LASIK using VisuMax and IntraLase femtosecond lasers for flap creation. However, the trend towards faster recovery of corneal sensitivity and TBUT observed in VisuMax-operated eyes may be attributable to improved technical specifications.Keywords: femtosecond laser, corneal sensitivity, tear film break-up time, Schirmer’s, corneal staining

Daphne CY Han,1,2 Jean Chen,3 Hla Myint Htoon,2 Donald TH Tan,1,2,4 Jodhbir S Mehta1,21Singapore National Eye Centre, 2Singapore Eye Research Institute, 3Yong Loo Lin School of Medicine, National University of Singapore, 4Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, SingaporeObjective: To compare the results of laser in situ keratomileusis for myopia using WaveLight® Allegretto Wave® Eye-Q® and Technolas® 217z excimer lasers.Method: A retrospective, comparative case series of 442 eyes matched for age and myopia: half each were treated with Allegretto's wavefront-optimized algorithm and Technolas PlanoScan. Outcome measures were postoperative mean logarithm of the minimum angle of resolution (logMAR) uncorrected visual acuity (UCVA), manifest refraction spherical equivalent (MRSE), cylinder, safety and efficacy indices, refractive predictability, and optical zone size selection. Refractive predictability of a subgroup treated for –2.50 to –4.0 diopter (D) was analyzed separately.Results: At mean follow-up of 80.5 days, mean logMAR UCVA, mean MRSE and mean postoperative cylinder were 0.02 ± 0.07 (range –0.12 to 0.30), 0.27 ± 0.36 D (range –1.25 to 1.50 D) and –0.33 ± 0.30 D (range 0.00 to –1.50 D) for Allegretto versus 0.02 ± 0.08 (range –0.12 to 0.40), 0.095 ± 0.47 D (range –1.25 to 1.13 D) and –0.44 ± 0.5 2 D (range 0.00 to –2.25 D) for Technolas (P = 0.98, 0.80 and 0.006). Mean safety and efficacy indices were 1.05 ± 0.13 (0.75–1.33) and 0.97 ± 0.13 (0.50–1.33) for Allegretto and 1.07 ± 0.14 (0.75–1.49) and 0.97 ± 0.17 (0.40–1.49) for Technolas (P = 0.23 and 0.69). Proportions of eyes achieving postoperative MRSE within ±1.0 D, ±0.5 D, and ±0.25 D were 98.2%, 91.9% and 75.6% for Allegretto and 99.1%, 97.8% and 72.4% for Technolas (P = 0.68, 0.20 and 0.51). Mean optical zone size selected was 6.48 ± 0.10 mm (range 6.0–6.5 mm) for Allegretto and 6.38 ± 0.19 mm (range 5.6–6.6 mm) for Technolas (P < 0.001). Of the subgroup with treatment between –2.5 and –4.0 D, 86.8% and 58.5% of eyes treated with Allegretto achieved postoperative MRSE within ±0.50 D and ±0.25 D versus 70.4% and 44.4% for Technolas (P = 0.006 and 0.057).Conclusion: No differences were seen in postoperative mean logMAR UCVA, MRSE, safety and efficacy indices between the two lasers. Allegretto produced less residual astigmatism, possibly improved refractive predictability, and required smaller optical zone selection.Keywords: LASIK, myopia, laser vision correction, conventional laser algorithm

Marcus Ang1,2, Jodhbir S Mehta1–4, Arundhati Anshu1,2, Hon Kiat Wong5, Hla M Htoon2, Donald Tan1–31Singapore National Eye Centre, 2Singapore Eye Research Institute, 3Department of Ophthalmology, National University Health Systems, 4Department of Clinical Sciences, Duke-NUS Graduate Medical School, 5Department of Ophthalmology, Tan Tock Seng Hospital, SingaporeBackground: The purpose of this study was to compare endothelial cell counts after Descemet’s stripping automated endothelial keratoplasty (DSAEK) and penetrating keratoplasty in Asian eyes.Methods: This was a retrospective study of patients from our prospective Singapore Corneal Transplant Study cohort who received corneal transplantation in 2006–2008. We compared eyes that underwent DSAEK or penetrating keratoplasty for Fuchs’ endothelial dystrophy or pseudophakic and aphakic bullous keratopathy. Clinical data, and donor and recipient characteristics were recorded. Of 241 patients who met our inclusion criteria, 68 underwent DSAEK and 173 underwent penetrating keratoplasty. The main outcome measure was endothelial cell loss at 1 year. Secondary outcome measures were graft survival and visual outcomes at 1-year follow-up.Results: There were no significant differences in baseline characteristics of patients between the treatment groups. Percent endothelial cell loss at 1-year follow-up was greater in penetrating keratoplasty eyes (40.9% ± 2.9%) compared with DSAEK eyes (22.4% ± 2.3%; P < 0.001). DSAEK-treated eyes had significantly superior uncorrected visual acuity (mean difference = 0.42 ± 0.0059; P < 0.001) and best spectacle-corrected visual acuity (mean difference = 0.14 ± 0.032; P < 0.001) as compared with penetrating keratoplasty-treated eyes. Penetrating keratoplasty-treated eyes had worse astigmatism as compared with DSAEK-treated eyes (-3.0 ± 2.1 versus -1.7 ± 0.8; P < 0.001). Graft survival at 1 year was comparable in both groups, ie, 66/68 (97.0%) DSAEK-treated eyes versus 158/173 (92.0%) of penetrating keratoplasty-treated eyes had clear grafts (P = 0.479).Conclusion: We report lower percent endothelial cell loss comparing DSAEK and penetrating keratoplasty at 1-year follow-up in Asian eyes, with comparable graft survival rates in both groups.Keywords: Descemet’s stripping automated endothelial keratoplasty, endothelial cell count, penetrating keratoplasty

Chelvin CA Sng1,2, Federico Luengo Gimeno1, Jodhbir S Mehta1,2, Hla Myint Htoon1, Donald T Tan1,21Singapore Eye Research Institute and Singapore National Eye Center, 2Department of Ophthalmology, National University Health System, SingaporePurpose: To evaluate the intraoperative changes in the donor lenticule, recipient cornea, and the reduction of interface fluid thickness during Descemet’s stripping and automated endothelial keratoplasty with EndoGlide™ (Angiotech Pharmaceuticals Inc, Vancouver, Canada) donor insertion, using intraoperative spectral-domain optical coherence tomography.Methods: Prospective observational case series of patients underwent Descemet’s stripping and automated endothelial keratoplasty using the EndoGlide inserter. Spectral-domain optical coherence tomography (iVue; Optovue Inc, Fremont, CA) with a handheld probe was used to image the cornea and anterior chamber. Standardized software was used to measure interface fluid gap, host cornea, and donor lenticule thicknesses during the following surgical stages of Descemet’s stripping and automated endothelial keratoplasty: (1) after donor insertion and immediately before full air tamponade; (2) after air tamponade and expression of fluid from venting incisions; (3) at 6 minutes of air tamponade; and (4) at 10 minutes of air tamponade.Results: Ten patients with a mean age of 74.9 ± 11.8 years were recruited. Spectral-domain optical coherence tomography measurements of the interface fluid gap after fluid was expressed through the venting incisions (P < 0.001), at 6 minutes of air tamponade (P < 0.001) and at 10 minutes of air tamponade (P < 0.001 and P = 0.001, respectively), were significantly decreased compared to the measurements immediately before air tamponade. Donor thickness increased significantly at 6 minutes of air tamponade (P = 0.004) but reduced by 10 minutes compared to immediately before air tamponade.Conclusion: Significant intraoperative changes in the donor, recipient cornea, and interface fluid thickness occurred following endothelial keratoplasty donor insertion.Keywords: Descemet’s stripping and automated endothelial keratoplasty, spectral-domain optical coherence tomography

Marcus Ang1,2, Hla M Htoon1,2, Howard Y Cajucom-Uy1,2, Donald Tan1–3, Jodhbir S Mehta1–41Singapore National Eye Centre, Bukit Merah, 2Singapore Eye Research Institute, Bukit Merah, 3Department of Ophthalmology, Yong Yoo Lin School of Medicine, National University of Singapore, Queenstown, 4Duke-NUS Graduate Medical School, Outram, SingaporeBackground: Descemet's stripping automated endothelial keratoplasty (DSAEK) has been shown to have superior refractive and visual results compared with penetrating keratoplasty, but higher rates of primary graft failure (PGF). This paper presents donor and surgical risk factors for PGF in DSAEK cases in Asian eyes.Design: Retrospective case-control study.Participants: All consecutive patients who underwent DSAEK at a tertiary referral teaching hospital from March 2006–December 2008.Methods: Donor details analyzed were: age of donor, cause of donor death, death to harvesting time, donor storage time, distribution distance of tissue, preoperative endothelial cell count. Surgical factors analyzed were: donor diameter, donor thickness, and method of donor insertion. These risk factors in cases of PGF were compared with patients with successful DSAEK as the control group.Main outcome measure: PGF.Results: A total of 124 DSAEK procedures were performed. Six DSAEK procedures (five eyes of five patients; one eye with two failures) resulted in PGF (4.8%). Significant risk factors were found for PGF to include graft insertion using a folding technique (odds ratio [OR], 34.03; 95% confidence interval [CI], 3.75–314.32; P = 0.0017) and a small donor diameter (OR, 39.94; 95% CI, 2.18–732.17; P = 0.013).Conclusion: The results of this study suggest that in Asian eyes with shallow anterior chambers, surgical trauma relating to the technique of donor insertion, and the use of a small donor are major risk factors for PGF following DSAEK.Keywords: DSAEK, PGF, penetrating keratoplasty

Karim Mohamed-Noriega,1,2 Jodhbir S Mehta1–41Tissue Engineering and Stem Cell Group, Singapore Eye Research Institute, 2Corneal and External Disease Service, Singapore National Eye Centre, 3Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, 4Department of Clinical Sciences, Duke-NUS Graduate Medical School, SingaporeAbstract: We report a case of spontaneous Descemet's membrane sweating of aqueous humor during a manual deep anterior lamellar keratoplasty (DALK) without perforation of Descemet's membrane. An 81-year-old female developed a neurotrophic central ulcer with descemetocele in the right eye, and her visual acuity was count fingers at 30 cm. She was unresponsive to medical treatment, and an uneventful manual DALK was performed. Six months after surgery, unaided visual acuity improved to 6/30. Seven months after surgery, the patient had a decrease in visual acuity to count fingers in the same eye. She was diagnosed as having corneal melting with a central descemetocele in the previous lamellar graft. A repeat manual DALK graft was performed. Lamellar dissection was performed starting from the edge of descemetocele, proceeding to the corneal periphery and maintaining the surgical plane of the previous DALK. During the surgical procedure, continuous and localized sweating of aqueous through Descemet's membrane was observed in the area of the descemetocele. After drying of the recipient bed, no visible perforation of Descemet's membrane was found. After removal of the previous DALK graft, a new stromal lamellar graft was sutured. The surgery was concluded without complications. One day after surgery, the graft was clear, with no detachment of Descemet's membrane. If Descemet's membrane sweating is observed during DALK and there is no visible perforation, the reason may be a hidden micron perforation in an intact Descemet's membrane. It is recommended to continue with surgery maintaining maximum diligence and low intraocular pressure to prevent extension of micron perforation.Keywords: deep anterior lamellar keratoplasty, perforation, Descemet's membrane, sweating

STUDY DESIGN.: Prospective case series. OBJECTIVE.: To evaluate the clinical and radiologic outcomes of short segment anterior scoliosis surgery with bone-on-bone apposition using a dual screw, dual rod system. SUMMARY OF BACKGROUND DATA.: Posterior segmental fixation for correction of AIS involves instrumentation of all the vertebrae included in the major curve. Our short segment anterior technique produces similar results by fusion of fewer levels. METHODS.: Forty-five patients operated between 1996 and 2004. Twenty-eight thoracic (Lenke 1) and 17 thoracolumbar (Lenke 5). The mean age was 19 years, 87% were females, and the mean follow-up was 72 months (range 28-121 months). We operated on curves less than 85° with 'total discectomy,' bone-on-bone apposition, and dual-screw, dual-rod fixation. RESULTS.: A mean of five vertebrae (four discs) were instrumented, with a mean operative time of 360 minutes, blood loss of 877 mL and a hospital stay of 9.1 day. LENKE 1.: The main preop thoracic curve was 52.5°, final postop curve 27.9°, by fusing five vertebrae, four discs. A spontaneous improvement of 47.5% of the lumbar compensatory curve was seen. The lower tilt angle corrected from 20.9° to 11°. LENKE 5.: The preoperative thoracolumbar major curve corrected from 50.5° to 18.3° (final) with fusion of four vertebrae, three discs. A spontaneous improvement of 37.4% occurred in the thoracic compensatory curve. The preop tilt angle improved from 27.7° to 8.3°.The sagittal and coronal balance was restored in all the patients. There were no neurologic, vascular, pulmonary, or implant-related complications. Union occurred within 3 months. All the patients returned to an unrestricted lifestyle within 4 months. CONCLUSION.: We report good results after surgical correction using our short segment bone-on-bone technique. Improvements were noted and maintained, over a 6-year period. [ABSTRACT FROM AUTHOR]

Topic: Development of evidence-based guidelines for keratorefractive lenticule extraction (KLEx)., Clinical Relevance: KLEx refers to various corneal refractive procedures involving removal of refractive lenticules of intrastromal corneal tissue, typically through a small incision, thereby eliminating creation of a corneal flap. This technique has rapidly gained popularity as a possible alternative to flap-based procedures; however, no clinical practice guidelines exist for KLEx., Methods: These evidence-based guidelines were developed following the WHO guidebook, utilizing the AGREE II tool, and adhering to the RIGHT statement. The body of evidence was drawn from eight literature databases, five clinical guideline databases, and two academic organizations. Recommendations were developed via a Delphi consensus of 44 global experts in refractive surgery, corneal diseases, retinal diseases, glaucoma, and optometry. The certainty of evidence, balance of benefits and harms, patient preferences and values, and economic evaluations were fully considered. The GRADE approach was employed to assess evidence quality and recommendation strengths., Results: From 385 initial clinical questions, 15 were identified, prompting a review of 250,717 studies, with 609 included for conducting and updating 26 and 2 systematic reviews, respectively. Subsequently, consensus was reached on 38 recommendations for preoperative screening, candidate selection, intraoperative quality control, operating principles, postoperative monitoring, and complication management. For KLEx, an effective and accurate refractive correction is attributed to various factors such as corneal thickness, degree of myopia, treatment nomogram, and optical zone. For KLEx-related complications that could affect vision, comprehensive and effective management strategies were proposed, particularly for wrong-plane dissection and difficult lenticule removal, suction loss, and perioperative infection. Customized surgical planning protocols and operative techniques were analyzed. Among all recommendations, 29 (76%) were labelled as "strong", each externally reviewed. The assessment of corneal biomechanical properties may help improve safety and predictability, though needing further validation. The development process also revealed several research gaps for enhancing KLEx safety., Conclusions: These guidelines provide evidence-based recommendations for KLEx in clinical practice, such as on preoperative screening for keratoconus, surgical planning, managements and prevention of complications and infection. The guidelines are expected to improve the safe and effective application of KLEx procedures and achieve more satisfactory visual correction., (Copyright © 2024. Published by Elsevier Inc.)

Over the past few decades, the expanded applications of in-vivo confocal microscopy (IVCM) have greatly enhanced the knowledge of a variety of conjunctival diseases. IVCM allows non-invasively detailed observation of tarsal, palpebral and bulbar conjunctiva, from the superficial to the substantia propria at the cellular level. IVCM has been shown as a powerful tool for the assessment of morphological changes in both physiological and pathological conditions. High-resolution images of different cellular phenotypes, together with quantifiable results, open new insights into understanding the mechanisms of conjunctival diseases, as well as provide valuable and longitudinal information for the diagnosis and therapeutic evaluation. This review aims to provide an overview of the current knowledge on the applications of IVCM on conjunctival disorders, including aging changes, dry eye-related morphological changes, glaucoma and glaucoma surgery-related morphological changes, conjunctival neoplasm, pterygium, allergic conjunctivitis, trachomatous scarring, and the conjunctiva-associated lymphoid tissue (CALT) changes. In this review, we highlight the key findings of previous studies and discusses the current limitations and challenges of IVCM in assessing the structural characteristics of the conjunctiva. Furthermore, we consider possible future directions for unlocking the full potential of IVCM applications. The insights presented here will contribute to a more comprehensive understanding of the applications of IVCM in conjunctival diseases., (© 2024. The Author(s).)

Purpose: To study the effect of corneal white-to-white diameter on Pentacam Scheimpflug cornea tomography and Corvis ST corneal visualization Scheimpflug technology parameters in myopic eyes., Methods: In this retrospective cross-sectional study, 190 eyes of 190 Chinese myopic patients (spherical equivalent range: -1.25 D to -11.00 D) assessed for refractive surgery using Pentacam and Corvis ST devices were included. Patients were divided into groups based on corneal diameter: group A <12 mm, and group B ≥12 mm. Age, gender, spherical equivalent, Pentacam variables, and Corvis ST variables were collected. Statistical analysis was performed using IBM SPSS Statistics (Version 28.0)., Results: There were 110 patients in group A and 80 patients in group B, with no statistically significant difference in age, gender, or spherical equivalence. For Pentacam data, group A had significantly higher Belin/Ambrosio Enhanced Ectasia Display (BAD-D) scores than group B (0.88 vs. 0.44) and pachymetric progression index (minimum, average, and maximum), and steeper front keratometric values, whereas group B had larger anterior chamber depth and maximum Ambrosio-relational thickness (ARTmax) (462.54 vs. 503.93). BAD-D indices, pachymetric progression indices, and front keratometric values had negative correlations with corneal diameter, whereas ARTmax and back keratometric values had positive correlations. For Corvis ST data, group A had a significantly higher corneal biomechanical index (CBI) (negatively correlated) while group B had a higher Ambrosio relational thickness to the horizontal profile (ARTh) (473.60 vs. 570.78) (positively correlated)., Conclusion: Corneal diameter influences both Pentacam and Corvis ST parameters, with smaller corneal diameters having a higher BAD-D and a lower ARTmax and ARTh. In addition, this is the first study to report a correlation between posterior surface corneal power and corneal diameter. As refractive surgery evaluation relies on these parameters, taking corneal diameter into account would improve both sensitivity and specificity in pre-refractive surgery screening for ectasia/keratoconus., (Copyright © 2024 Copyright: © 2024 Indian Journal of Ophthalmology.)

Purpose: Children undergoing either posterior spinal fusion (PSF) or index insertion of growing rods for neuromuscular or genetic/syndromic scoliosis may require post-operative care on the paediatric intensive care unit (PICU). Demands on this limited resource result in frequent bed shortage related cancellations. In response, an ad-hoc or 'pop-up' ward-based high-dependency unit (POPUP-HDU) was developed. This converts a ward bed to POP-HDU bed for the required time. This study assesses the safety and efficacy of postoperative management that utilises POPUP-HDU as an alternative to a PICU bed., Methods: Retrospective review of 111 consecutive children undergoing posterior surgery for scoliosis between June 2016 and April 2023. The inclusion criteria included a diagnosis of genetic/syndromic or neuromuscular scoliosis; PSF or primary insertion of distraction-based growth rods and requirement for postoperative care in a PICU. We excluded those children that were mandated to go to PICU post-operatively for any reason by the anaesthetic team., Results: 49 patients (mean age 13.0 years) were managed on PICU, and 62 (mean age 11.4 years) on POPUP-HDU. The groups were matched with respect to body weight, curve magnitude, operative duration, type of fusion procedure performed, the presence of cardiac malformations, the use of home breathing support, the number of operated levels, pelvic instrumentation and intraoperative blood loss. 8 patients in the PICU, and 16 in the POP-HDU groups were readmitted back to PICU following step-down to the hospital ward (p = 0.27). The median PICU length of stay was 1 day in the PICU group and less than a day in POPUP-HDU (for those that needed to be subsequently admitted to PICU). The median total length of hospital stay was 10 days in the PICU group, and 8 days in POPUP-HDU (p < 0.05). 14 patients developed medical complications in the PICU group, compared to 19 in POPUP-HDU. There were no bedshortage cancellations in POPUP-HDU, compared to 23 in PICU., Conclusions: For children with neuromuscular, genetic or syndromic scoliosis undergoing PSF or growth rods that are not deemed suitable for immediate ward-level post-operative care, POPUP-HDU provided a safe alternative to PICU for appropriate patients and was associated with shorter hospital stay and fewer cancellations for lack of PICU beds., Level of Evidence: Therapeutic Level III., (© 2024. The Author(s), under exclusive licence to Scoliosis Research Society.)

Background: Infectious keratitis (IK) is the leading cause of corneal blindness globally. Deep learning (DL) is an emerging tool for medical diagnosis, though its value in IK is unclear. We aimed to assess the diagnostic accuracy of DL for IK and its comparative accuracy with ophthalmologists., Methods: In this systematic review and meta-analysis, we searched EMBASE, MEDLINE, and clinical registries for studies related to DL for IK published between 1974 and July 16, 2024. We performed meta-analyses using bivariate models to estimate summary sensitivities and specificities. This systematic review was registered with PROSPERO (CRD42022348596)., Findings: Of 963 studies identified, 35 studies (136,401 corneal images from >56,011 patients) were included. Most studies had low risk of bias (68.6%) and low applicability concern (91.4%) in all domains of QUADAS-2, except the index test domain. Against the reference standard of expert consensus and/or microbiological results (seven external validation studies; 10,675 images), the summary estimates (95% CI) for sensitivity and specificity of DL for IK were 86.2% (71.6-93.9) and 96.3% (91.5-98.5). From 28 internal validation studies (16,059 images), summary estimates for sensitivity and specificity were 91.6% (86.8-94.8) and 90.7% (84.8-94.5). Based on seven studies (4007 images), DL and ophthalmologists had comparable summary sensitivity [89.2% (82.2-93.6) versus 82.2% (71.5-89.5); P = 0.20] and specificity [(93.2% (85.5-97.0) versus 89.6% (78.8-95.2); P = 0.45]., Interpretation: DL models may have good diagnostic accuracy for IK and comparable performance to ophthalmologists. These findings should be interpreted with caution due to the image-based analysis that did not account for potential correlation within individuals, relatively homogeneous population studies, lack of pre-specification of DL thresholds, and limited external validation. Future studies should improve their reporting, data diversity, external validation, transparency, and explainability to increase the reliability and generalisability of DL models for clinical deployment., Funding: NIH, Wellcome Trust, MRC, Fight for Sight, BHP, and ESCRS., Competing Interests: HA is the Chief Scientific Officer of Preemptive Medicine and Health, Flagship Pioneering., (© 2024 The Author(s).)

Abstract: An integrated cell, tissue, and eye bank is vital to meet the evolving needs of ocular transplant therapies. In addition to traditional corneal transplant tissues, it encompasses processing and delivery of transplant materials for newer treatments like cell-based therapies and gene-modified products, adhering to rigorous standards, optimizing tissue utilization with comprehensive services for surgeons., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc.)

Purpose: To assess the visual outcomes in patients with cataract implanted with a small-aperture intraocular lens (IOL) in eyes with aberrated corneas., Methods: This prospective, non-interventional, single-center clinical study was conducted at Singapore National Eye Centre, Singapore. Twenty-one patients with aberrated corneas had IC-8 IOL (Bausch & Lomb, Inc) implantation. An aberrated cornea was defined as from natural causes: keratoconus (n = 1, 4.8%), high coma (n = 2, 9.5%), corneal scar (n = 1, 4.8%), or iatrogenic causes: keratorefractive procedure (n = 17, 86%). Uncorrected and corrected visual acuities were measured at distance (600 cm) (UDVA and CDVA), intermediate (66.7 cm) (UIVA and CIVA), and near (40 cm) (UNVA and CIVA). Defocus curve was tested monocularly and binocularly. Contrast sensitivity (CS) was measured under photopic and mesopic conditions with and without glare., Results: In IC-8 eyes, the mean ± standard deviation UDVA, UIVA, and UNVA was 0.24 ± 0.18, 0.19 ± 0.18, and 0.14 ± 0.14 logMAR, respectively. Mean CDVA, CIVA, and CNVA in IC-8 eyes was 0.12 ± 0.17, 0.16 ± 0.15, and 0.19 ± 0.13 logMAR, respectively. Binocular mean UDVA, UIVA, and UNVA was 0.07 ± 0.10, 0.07 ± 0.10, and 0.13 ± 0.12 logMAR, respectively. Defocus curve testing yielded a depth of focus of 1.50 D monocularly and 2.00 D binocularly at a 0.2 logMAR threshold. Photopic binocular CS with and without glare improved over monocular CS of IC-8 and fellow eyes under all spatial frequencies. Mesopic binocular CS with and without glare were similar among monocular IC-8 and fellow eyes across spatial frequencies. Most patients reported low levels of visual symptoms., Conclusions: The IC-8 IOL provides good monocular and binocular visual outcomes for patients with cataract who had aberrated corneas. [ J Refract Surg . 2024;40(10):e716-e723.] .

Antimicrobial resistance (AMR) is a serious threat to global public health, with approximately 5 million deaths associated with bacterial AMR in 2019. Tackling AMR requires a multifaceted and cohesive approach that ranges from increased understanding of mechanisms and drivers at the individual and population levels, AMR surveillance, antimicrobial stewardship, improved infection prevention and control measures, and strengthened global policies and funding to development of novel antimicrobial therapeutic strategies. In this rapidly advancing field, this Review provides a concise update on AMR, encompassing epidemiology, evolution, underlying mechanisms (primarily those related to last-line or newer generation of antibiotics), infection prevention and control measures, access to antibiotics, antimicrobial stewardship, AMR surveillance, and emerging non-antibiotic therapeutic approaches. The Review also discusses the potential roles of artificial intelligence in addressing AMR, including antimicrobial susceptibility testing, AMR surveillance, antimicrobial stewardship, diagnosis, and antimicrobial drug discovery and development. This Review highlights the urgent need for addressing the global effects of AMR and for rapid advancement of relevant technology in this dynamic field., Competing Interests: Declaration of interests CFN provides consulting services to Invaio Sciences and is a member of the Scientific Advisory Boards of Nowture SL, Peptidus, and Phare Bio. CFN is also on the advisory board of the Peptide Drug Hunting Consortium. REWH is an inventor who holds many patents on antimicrobial and antibiofilm peptides that have been assigned to The University of British Columbia and licensed to ABT Innovations, in which REWH has an ownership position and is the CEO. All other authors declare no competing interests., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

High-order diffraction (HOD) from optical microstructures is undesirable in many applications because of the accompanying ghosting patterns and loss of efficiency. In contrast to suppressing HOD with subwavelength structures that challenge the fabrication of large-scale devices, managing HOD is less developed due to the lack of an efficient method for independently manipulating HOD. Here, we report independent manipulation of HODs, which are unexploited for subdiffraction-limit focusing in diffractive lenses, through an analytical formula that correlates the diffraction order and the width of each zone. The large spatial frequencies offered by the HODs enable our lenses to reduce the lateral focal size down to 0.44 λ even without any subwavelength feature (indispensable in most high-NA diffractive lenses), facilitating large-scale manufacture. Experimentally, we demonstrate high-order lens-based confocal imaging with a center-to-center dry resolution of 190 nm, the highest among visible-light confocal microscopies, and laser-ablation lithography with achieved direct-writing resolution of 400 nm (0.385 λ)., (© 2024. The Author(s).)

Study Design: Retrospective cohort study., Objective: Magnetic Resonance Imaging (MRI) is often regarded as the gold standard for spinal pathology, as it provides good structural visualisation. SPECT-CT, however, provides combined structural and functional information. There is a paucity of literature comparing SPECT-CT with MRI in the spine. Our aim was to determine whether SPECT-CT provides additional information to MRI in individuals with complex spinal pathology, including deformity, which altered management., Methods: We conducted a retrospective review of all individuals seen at our tertiary spinal unit that were investigated with both MRI and SPECT-CT of the spine between 2007-2020. We reviewed imaging reports, and collated diagnoses, surgical treatment and the relative contributions of MRI and SPECT-CT to management decisions., Results: 104 individuals identified, with a mean age of 30 years (89 females and 15 males). Diagnostic categories were adolescent, adult, and congenital deformity, degenerative pathology, and miscellaneous pathology. MRI returned positive findings in 58 (55.8%), and SPECT-CT in 41 (39.4%) cases. SPECT-CT identified 10 cases of facet joint degeneration, 5 of increased uptake around metalwork suggestive of loosening, 1 pseudoarthrosis, 1 partial failure of fusion and 1 osteoid osteoma which were not reported on MRI, all in individuals who had previously undergone spinal instrumentation. Despite this, SPECT-CT only altered management for 6 individuals (5.8%)., Conclusion: MRI is less useful in the setting of previous instrumentation due to metal artefact. Where MRI is inconclusive, particularly in individuals with previous spinal instrumentation, SPECT-CT may provide a diagnosis, but is not recommended as primary imaging., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Purpose: To investigate the tear proteomic and neuromediator profiles, in vivo confocal microscopy (IVCM) imaging features, and clinical manifestations in neuropathic corneal pain (NCP) patients., Design: Cross-sectional study., Methods: A total of 20 NCP patients and 20 age-matched controls were recruited. All subjects were evaluated by corneal sensitivity, Schirmer test, tear break-up time, and corneal and ocular surface staining, Ocular Surface Disease Index and Ocular Pain Assessment Survey questionnaires were administered, as well as IVCM examinations for corneal nerves, microneruomas, and epithelial and dendritic cells. Tears were collected for neuromediator and proteomic analysis using enzyme-linked immunosorbent assay and data-independent acquisition mass spectrometry., Results: Burning and sensitivity to light were the 2 most common symptoms in NCP. A total of 188 significantly dysregulated proteins, such as elevated metallothionein-2, creatine kinases B-type, vesicle-associated membrane protein 2, neurofilament light polypeptide, and myelin basic protein, were identified in the NCP patients. The top 10 dysregulated biological pathways in NCP include neurotoxicity, axonal signaling, wound healing, neutrophil degradation, apoptosis, thrombin signaling mitochondrial dysfunction, and RHOGDI and P70S6K signaling pathways. Compared to controls, the NCP cohort presented with significantly decreased corneal sensitivity (P < .001), decreased corneal nerve fiber length (P = .003), corneal nerve fiber density (P = .006), and nerve fiber fractal dimension (P = .033), as well as increased corneal nerve fiber width (P = .002), increased length, total area and perimeter of microneuromas (P < .001, P < .001, P = .019), smaller corneal epithelial size (P = .017), and higher nerve growth factor level in tears (P = .006)., Conclusions: These clinical manifestations, imaging features, and molecular characterizations would contribute to the diagnostics and potential therapeutic targets for NCP., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Corneal diseases represent a growing public health burden, especially in resource-limited settings lacking access to specialized eye care. Artificial intelligence (AI) offers promising solutions for automating the diagnosis and management of corneal conditions. This narrative review examines the application of AI in corneal diseases, focusing on keratoconus, infectious keratitis, pterygium, dry eye disease, Fuchs endothelial corneal dystrophy, and corneal transplantation. AI models integrating diverse imaging modalities (e.g., corneal topography, slit-lamp, and anterior segment OCT images) and clinical data have demonstrated high diagnostic accuracy, often outperforming human experts. Emerging trends include the incorporation of biomechanical data to enhance keratoconus detection, leveraging in vivo confocal microscopy for diagnosing infectious keratitis, and employing multimodal approaches for comprehensive disease analysis. Additionally, AI has shown potential in predicting disease progression, treatment outcomes, and postoperative complications in corneal transplantation. While challenges remain such as population heterogeneity, limited external validation, and the "black box" nature of some models, ongoing advancement in explainable AI, data augmentation, and improved regulatory frameworks can serve to address these limitations., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.)

Purpose: To describe the prevalence and antibiotic resistance profiles of Pseudomonas aeruginosa isolated from the Asia Cornea Society Infectious Keratitis Study (ACSIKS)., Methods: All bacterial isolates from ACSIKS underwent repeat microbiological identification in a central repository in Singapore. Minimum inhibitory concentration (MIC) determination was conducted for isolates of P. aeruginosa against thirteen antibiotics from 6 different classes, and categorized based on Clinical Laboratory Standard Institutes' reference ranges. The percentage rates of resistance (non-susceptibility) to each antibiotic included isolates of both intermediate and complete resistance. Multi-drug resistance (MDR) was defined as non-susceptibility to at least one agent in three or more antimicrobial classes., Results: Of the 1493 unique bacterial specimens obtained from ACSIKS, 319 isolates were of P. aeruginosa. The majority of isolates were from centers in India (n = 118, 37%), Singapore (n = 90, 28.2%), Hong Kong (n = 31, 9.7%) and Thailand (n = 30, 9.4%). The cumulative antibiotic resistance rate was the greatest for polymyxin B (100%), ciprofloxacin (17.6%) and moxifloxacin (16.9%), and lowest for cefepime (11.6%) and amikacin (13.5%). Isolates from India demonstrated the highest antibiotic resistance rates of all the centers, and included moxifloxacin (47.5%) and ciprofloxacin (39.8%). Forty-eight of the 59 MDR isolates also originated from India. Antibiotic resistance rates were significantly lower in the other ACSIKS centers, and were typically less than 10%., Conclusions: The antibiotic resistance profiles of P. aeruginosa varied between different countries. While it was low for most countries, substantial antibiotic resistance and a significant number of multi-drug resistant isolates were noted in the centers from India., (© 2024. The Author(s).)

Purpose: To investigate and compare the quality of life (QoL) and symptomatology between neuropathic corneal pain (NCP) and dry eye disease (DED)., Methods: We recruited 150 patients, comprising 50 patients with NCP and 100 patients with DED. Patients' symptoms and QoL were evaluated using the Ocular Pain Assessment Survey and Ocular Surface Disease Index questionnaires. Ocular surface assessments were also performed., Results: Patients with NCP demonstrated significantly lower Oxford and National Eye Institute scores for ocular surface and corneal staining, respectively, and a better tear break-up time than patients with DED. However, patients with NCP reported significantly worse scores on most of the Ocular Pain Assessment Survey questions and significantly more severe overall pain (P = 0.019), maximal and average ocular pain and nonocular pain (all P < 0.05). The NCP group reported significantly worse QoL in all aspects of daily living (all P < 0.001). Patients with NCP spent more time thinking about their eye pain and reported significantly higher pain intensities than patients with DED when exposed to chemical and mechanical stimuli (all P ≤ 0.008). Burning sensation and photophobia were significantly more frequent in patients with NCP (P = 0.032 and P = 0.012, respectively). Similarly, the NCP group reported significantly worse total Ocular Surface Disease Index scores, significantly more frequent vision-related function impairment and painful or sore eyes than the DED group (P = 0.029, P = 0.031, and P = 0.014, respectively)., Conclusions: Compared with DED, NCP is more debilitating, leading to more severe and frequent symptoms, and greater negative impact on all aspects of QoL., Competing Interests: The authors have no funding or conflicts of interest to disclose., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc.)

Background/aim: To evaluate differences in ocular complications of Stevens Johnson Syndrome (SJS)/Toxic Epidermal Necrolysis (TEN) patients receiving either systemic IVIG or Ciclosporin (CsA) as initial treatments., Methods: Retrospective review of consecutive patients admitted for SJS/TEN at the Singapore General Hospital (SGH) from 2011 to 2017 who received either IVIG or Ciclosporin at the onset of the disease and had ophthalmological follow-up of at least 6 months were included. Acute ocular severity of SJS/TEN was graded using the Gregory grading score; chronic ocular complications were graded using the Sotozono system., Results: A total of 18 subjects were included for analysis, with eight in the IVIG group and 10 in the CsA group. There were no significant differences in acute Gregory severity grading between the two groups. The CsA group had a trend towards worse overall chronic Sotozono grading scores compared to the IVIG group (median [IQR]: 2 [0-3] vs. 1 [0-6.5], p  = 0.27), with a higher incidence of acute severe cornea involvement (60% vs. 25%, p  = 0.93) and chronic corneal and eyelid involvement in the former than the latter. SJS/TEN patients with worse acute ocular involvement were more likely to have TEN and perianal mucosal involvement (50% vs. 0, p  = 0.01)., Conclusion: Compared to those who received IVIG, SJS/TEN patients who received CsA at the acute disease stage, seemed to have worse acute corneal and chronic corneal and eyelid complications. Larger studies are needed to confirm this finding., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Foo, Yueh, Mehta and Ong.)

Purpose: To predict 10-year graft survival after deep anterior lamellar keratoplasty (DALK) and penetrating keratoplasty (PK) using a machine learning (ML)-based interpretable risk score., Methods: Singapore Corneal Transplant Registry patients (n = 1687) who underwent DALK (n = 524) or PK (n = 1163) for optical indications (excluding endothelial diseases) were followed up for 10 years. Variable importance scores from random survival forests were used to identify variables associated with graft survival. Parsimonious analysis using nested Cox models selected the top factors. An ML-based clinical score generator (AutoScore) converted identified variables into an interpretable risk score. Predictive performance was evaluated using Kaplan-Meier (KM) curves and time-integrated AUC (iAUC) on an independent testing set., Results: Mean recipient age was 51.8 years, 54.1% were male, and majority were Chinese (60.0%). Surgical indications included corneal scar (46.5%), keratoconus (18.3%), and regraft (16.2%). Five-year and ten-year KM survival was 93.4% and 92.3% for DALK, compared with 67.6% and 56.6% for PK (log-rank P < 0.001). Five factors were identified by ML algorithm as predictors of 10-year graft survival: recipient sex, preoperative visual acuity, choice of procedure, surgical indication, and active inflammation. AutoScore stratified participants into low-risk and high-risk groups-with KM survival of 73.6% and 39.0%, respectively (log-rank P < 0.001). ML analysis outperformed traditional Cox regression in predicting graft survival beyond 5 years (iAUC 0.75 vs. 0.69)., Conclusions: A combination of ML and traditional techniques identified factors associated with graft failure to derive a clinically interpretable risk score to stratify PK and DALK patients-a technique that may be replicated in other corneal transplant programs., Competing Interests: The authors have no funding or conflicts of interest to disclose., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Little is known about the effects of different seasons on the cryopreservation success of buffalo sperm in terms of kinematics and sperm functional parameters., Objective: To study the effect of three seasons (winter, comfort and summer) and cryopreservation on sperm kinematics and functional properties in buffalo bulls., Materials and Methods: Semen ejaculates (n = 90) collected during three seasons i.e. winter (n = 30), comfort (n = 30), summer (n = 30) were evaluated for sperm kinematics and functional properties., Results: Sperm kinematics with respect to total (TM), progressive (PM) and rapid motility (RM) was higher (P < 0.05) in fresh sperm compared to sperm that had been frozen-thawed. Similarly, all kinematic parameters [viz. average path velocity (VAP), straight linear velocity (VSL), curvilinear velocity (VCL), beats cross frequency (BCF), lateral head displacement (ALH), linearity (LIN) and straightness (STR)] were higher (P < 0.01) at the fresh stage. With respect to season, frozen-thawed semen TM (57.67 ± 115 %), PM (50.2 ± 1.15 %) and RM (51.6 ± 1.19 %) were higher (P < 0.01) when using sperm collected during winter. The stage of cryopreservation (i.e., equilibration and freeze-thawing) also showed significant effects (P < 0.01) on mitochondrial superoxide positive status (MSPS), mitochondrial membrane potential (MMP), acrosome status and intra-cellular calcium status., Conclusion: The season of sperm collection and cryopreservation have significant effects on buffalo bull sperm kinematics and functional properties. Doi.org/10.54680/fr24410110612.

The aim of our study is to investigate the feasibility and outcomes of using a femtosecond laser (FSL) platform (Ziemer LDV Z8) for deep anterior lamellar keratoplasty (DALK), enabling the creation of mushroom-shaped graft-host junctions, lamellar cuts, and intrastromal tunnels, to facilitate the big bubble, in one step. We included wet lab experiments on nine porcine eyes to assess the laser accuracy and cuts depth using an anterior segment (AS) OCT. This was followed by an interventional prospective case series on 10 eyes with variant corneal pathologies. The Z8 system, with in-built intraoperative optical coherence tomography (iOCT), guided corneal scans and directed the cuts. ASOCT showed visible mushroom configurations, lamellar cuts, and tunnels. Deviations from the target were 1.6%, 2.6%, and 3.5%. Anterior lamellar removal was easy in all clinical cases, including corneal scarring. The intrastromal tunnel was found at the preset location and the mushroom configuration was acquired. A big bubble was achieved in all cases. Type 1, 2, and 3 bubbles were formed in eight, one, and one case, respectively. We describe a new approach to DALK in which the in-built iOCT-guided FSL enables safe, precise, controlled, and reproducible desired cuts in one step. The preliminary clinical outcomes were favorable.

Previous studies have shown that the nucleus could offer structural support to the lens capsule. This study investigated the biomechanical performance of porcine lens with and without nucleus for 4 mm, 4.5 mm, 5 mm, 5.5 mm and 6 mm capsulotomy and its potential impact on the stretch ratio of capsular bag when the anterior capsulotomy edge was stretched. Our simulation results showed higher strain for the capsular bag with nucleus, which is crucial for the porcine lens to tolerate more stretch without failure. This simulation could support future study on the optimization of capsulotomy based on patient specific condition, that is, the geometry of lens.

Intrastromal cell therapy utilizing quiescent corneal stromal keratocytes (qCSKs) from human donor corneas emerges as a promising treatment for corneal opacities, aiming to overcome limitations of traditional surgeries by reducing procedural complexity and donor dependency. This investigation demonstrates the therapeutic efficacy of qCSKs in a male rat model of corneal stromal opacity, underscoring the significance of cell-delivery quality and keratocyte differentiation in mediating corneal opacity resolution and visual function recovery. Quiescent CSKs-treated rats display improvements in escape latency and efficiency compared to wounded, non-treated rats in a Morris water maze, demonstrating improved visual acuity, while stromal fibroblasts-treated rats do not. Advanced imaging, including multiphoton microscopy, small-angle X-ray scattering, and transmission electron microscopy, revealed that qCSK therapy replicates the native cornea's collagen fibril morphometry, matrix order, and ultrastructural architecture. These findings, supported by the expression of keratan sulfate proteoglycans, validate qCSKs as a potential therapeutic solution for corneal opacities., (© 2024. The Author(s).)

Keratoprosthesis (KPro) implantation is frequently the only recourse for patients with severe corneal disease. However, problems arise due to inadequate biointegration of the KPro, particularly the PMMA optical cylinder, such as tissue detachment, tissue melting, or eye-threatening infection in the interface. Here, using the AuroKPro as a model prosthesis, a surface functionalization approach─coating the optical cylinder with nanohydroxyapatite (nHAp)─was trialed in rabbit eyes with and without a proceeding chemical injury. In chemically injured eyes, which simulated total limbal epithelial stem cell deficiency, clear benefits were conferred by the coating. The total modified Hackett-McDonald score and area of tissue apposition differences 12 weeks after implantation were 5.0 and 22.5%, respectively. Mechanical push-in tests revealed that 31.8% greater work was required to detach the tissues. These differences were less marked in uninjured eyes, which showed total score and tissue apposition differences of 2.5 and 11.5%, respectively, and a work difference of 23.5%. The improved biointegration could be contributed by the attenuated expression of fibronectin ( p = 0.036), collagen 3A1 ( p = 0.033), and α-smooth muscle actin ( p = 0.045)─proteins typically upregulated during nonadherent fibrous capsule envelopment of bioinert material─adjacent to the optical cylinders. The coating also appeared to induce a less immunogenic milieu in the ocular surface tissue, evidenced by the markedly lower expression of tear proteins associated with immune and stimulus responses. Collectively, the level of these tear proteins in eyes with coated prostheses was 1.1 ± 13.0% of naïve eyes: substantially lower than with noncoated KPros (246.5 ± 79.3% of naïve, p = 0.038). Together, our results indicated that nHAp coating may reduce the risk of prosthesis failure in severely injured eyes, which are representative of the cohort of KPro patients.

There are some syndromes that present with unique manifestations pertaining to the spinal column. A good working understanding of these common syndromes is useful for the spinal deformity surgeons and related healthcare providers. This review attempts to encompass these unique features and discuss them in three broad groups: hypermobility syndromes, muscle pathology-related syndromes, and syndromes related to poor bone quality. This review explores the features of these syndromes underpinning the aspects of surgical and medical management. This review represents the proceedings of the Paediatric Half-Day Course at the 57th Annual Meeting of the Scoliosis Research Society., (© 2024. The Author(s), under exclusive licence to Scoliosis Research Society.)

Purpose: To compare differences in corneal densitometry (CD) and higher order aberrations (HOAs) in eyes that underwent small incision lenticule extraction (SMILE) and femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK) for the treatment of myopia and myopic astigmatism at postoperative months 3, 6, and 12, and to evaluate their changes in a separate cohort of eyes after SMILE enhancement., Methods: In this prospective, randomized, paired-eye clinical trial, consecutive eligible participants were randomized to undergo SMILE or FS-LASIK in either eye. Main outcome measures were CD and HOAs preoperatively and at 3, 6, and 12 months postoperatively. A separate cohort of consecutive patients who had SMILE and underwent enhancement were also included for comparison., Results: For CD, no significant differences were found between SMILE and FS-LASIK up to month 12. For HOA measured by wavefront aberrometry, both SMILE and FS-LASIK had an increase in total root mean square (RMS) HOAs, spherical aberration (SA), and vertical coma up to month 12. SMILE had an additional increase in vertical quatrefoil, and FS-LASIK had an increase in horizontal coma at month 12. FS-LASIK had higher SA than SMILE, whereas SMILE had higher vertical quatrefoil than FS-LASIK at month 12. Central and posterior zone CD had significantly decreased after SMILE enhancement compared to after primary SMILE up to 2 years after enhancement. RMS HOAs, lower order aberrations, and SA were all increased after SMILE enhancement compared to after primary SMILE., Conclusions: SMILE induced lower SA but higher vertical quatrefoil than FS-LASIK at 1 year. Both SMILE and FS-LASIK had similar increases in RMS HOAs and vertical coma up to 1 year. There were no differences in CD between both groups. SMILE enhancement additionally had decreased central and posterior CD but greater RMS HOAs and SA compared to primary SMILE. [ J Refract Surg . 2024;40(5):e291-e303.] .

Purpose: Magnetic Resonance Imaging (MRI) is frequently utilised to aid in the comprehensive assessment of back pain, while dual-energy x-ray absorptiometry (DEXA) is the gold standard test for the assessment of bone density. Assessing bone density on MRI could reduce costs and avoid exposing patients to ionising radiation. The aim of this paper is to investigate whether the relative signal intensity of vertebral bodies compared to other structures can detect osteoporosis on MRI., Methods: 100 patients that had undergone both a lumbar spine MRI and a DEXA scan were identified. The T1 and T2 signal intensity of L1-L4 vertebral bodies (VB), cerebro-spinal fluid (CSF), and psoas muscle were measured within a 1-cm 2 region of interest (ROI), and the signal intensity ratios were calculated. The ratios were stratified as normal, osteopenic, or osteoporotic based on DEXA T-scores., Results: The T1 VB /T1 CSF ratio was significantly higher in the osteoporotic group than the normal and osteopenic groups (p < 0.001). The T1 VB /T1 CSF ratio had excellent discrimination (AUC = 0.841) for the presence of osteoporosis. The Pearson correlation coefficient between the DEXA T-score and the T1 VB/T1 CSF ratio was -0.474 (p < 0.001). The intra-observer (ICC = 0.910, 95% CI = 0.757-0.966) and inter-observer reliability (ICC = 0.927, 95% CI = 0.824-0.970) were excellent. In our cohort, a T1 VB / T1 CSF ratio of greater than 4 is 66.7% sensitive but 90.0% specific for the presence of osteoporosis., Conclusion: A high T1 VB/T1 CSF ratio suggests osteoporosis on MRI. Prospective validation is needed to confirm these findings., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: The aim of this study was to investigate age-related changes in corneal nerves and corneal epithelial cell parameters and to establish age-adjusted reference values., Methods: A total of 7025 corneal nerve images and 4215 corneal epithelial images obtained using in vivo confocal microscopy from 281 eyes of 143 healthy participants were included. Seven corneal nerve parameters and 3 corneal epithelial cell parameters were quantified using 2 automatic analytic software and analyzed across 6 age groups ranging from 21 to 80 years., Results: There was a declining trend in all 7 nerve parameters with advancing age. In particular, corneal nerve fiber length and corneal nerve fiber density demonstrated a significant decrease in subjects aged 65 years or older compared with subjects younger than 65 years (10.8 ± 2.6 mm/mm 2 vs. 9.9 ± 2.0 mm/mm 2 , P = 0.011 in corneal nerve fiber length; 15.8 ± 5.2 fibers/mm 2 vs. 14.4 ± 4.3 fibers/mm 2 , P = 0.046 in corneal nerve fiber density), whereas corneal nerve fractal dimension demonstrated a borderline significant decrease ( P = 0.057). Similarly, there was a general declining trend in all epithelial cell parameters with advancing age. Corneal epithelial cell circularity was significantly lower in subjects aged 65 years and older as compared to subjects younger than 65 years (0.722 ± 0.021 μm 2 vs. 0.714 ± 0.021 μm 2 ; P = 0.011)., Conclusions: Advancing age results in reduced corneal nerve metrics and alteration of corneal cell morphology. Aging effects should be considered when evaluating patients with corneal neuropathy., Competing Interests: The authors have no funding or conflicts of interest to disclose., (Copyright © 2023 The Author(s). Published by Wolters Kluwer Health, Inc.)

Background: To describe the diagnostic performance of a deep learning (DL) algorithm in detecting Fuchs endothelial corneal dystrophy (FECD) based on specular microscopy (SM) and to reliably detect widefield peripheral SM images with an endothelial cell density (ECD) > 1000 cells/mm 2 ., Methods: Five hundred and forty-seven subjects had SM imaging performed for the central cornea endothelium. One hundred and seventy-three images had FECD, while 602 images had other diagnoses. Using fivefold cross-validation on the dataset containing 775 central SM images combined with ECD, coefficient of variation (CV) and hexagonal endothelial cell ratio (HEX), the first DL model was trained to discriminate FECD from other images and was further tested on an external set of 180 images. In eyes with FECD, a separate DL model was trained with 753 central/paracentral SM images to detect SM with ECD > 1000 cells/mm 2 and tested on 557 peripheral SM images. Area under curve (AUC), sensitivity and specificity were evaluated., Results: The first model achieved an AUC of 0.96 with 0.91 sensitivity and 0.91 specificity in detecting FECD from other images. With an external validation set, the model achieved an AUC of 0.77, with a sensitivity of 0.69 and specificity of 0.68 in differentiating FECD from other diagnoses. The second model achieved an AUC of 0.88 with 0.79 sensitivity and 0.78 specificity in detecting peripheral SM images with ECD > 1000 cells/mm 2 ., Conclusions: Our pilot study developed a DL model that could reliably detect FECD from other SM images and identify widefield SM images with ECD > 1000 cells/mm 2 in eyes with FECD. This could be the foundation for future DL models to track progression of eyes with FECD and identify candidates suitable for therapies such as Descemet stripping only., (© 2024. The Author(s).)

Fuchs endothelial corneal dystrophy (FECD) is a complex genetic disorder characterized by the slow and progressive degeneration of corneal endothelial cells. Thus, it may result in corneal endothelial decompensation and irreversible corneal edema. Moreover, FECD is associated with alterations in all corneal layers, such as thickening of the Descemet membrane, stromal scarring, subepithelial fibrosis, and the formation of epithelial bullae. Hence, anterior segment imaging devices that enable precise measurement of functional and anatomical changes in the cornea are essential for the management of FECD. In this review, the authors will introduce studies on the application of various imaging modalities, such as anterior segment optical coherence tomography, Scheimpflug corneal tomography, specular microscopy, in vitro confocal microscopy, and retroillumination photography, in the diagnosis and monitoring of FECD and discuss the results of these studies. The application of novel technologies, including image processing technology and artificial intelligence, that are expected to further enhance the accuracy, precision, and speed of the imaging technologies will also be discussed.